Multirheostat



Jan. 11, 1927. 1,613,994

0. W. GROSE ET AL MULTIRHEOSTAT Filed June 2, 1926 2 Sheets-Sheet 2 I nventom 0. Hfflrase fiubertliz/schez;

Attorney Patented Jan. 11, 1927. v

UNITED STATES PATENT OFFICE.

ORAN W. GBOSE, OF VERMILION, ILLINOIS, AND HUBERT FISHER, OF TERRE HAUTE,

4 INDIANA.

MULTIRHEOSTAT.

Application filed June 2, 1926. Serial No. 113,203.

The present invention relates to a rheostat stance, one-half ohm. Each group 8 is in 5. and aims to provide a device of this nature electrical engagement with the adjacent concapable of fine adjustments, and provided tact C, as is more clearly shown in Fig. 5. with a compact and simple construction that It will be noted in Figs. 3 and 5, that the may be manufactured at a low cost. contact C denoted specifically by the nu Another very important object of the inmeral 9, is a dead contact, that is, has no 60 vention resides in the provision of a device connection with any group of the wire on of this nature with an adjustable structure ring 7. that is easy to manipulate, thoroughly ef- A stop 10 is mounted on this contact 9. A

10 ficient and reliable in operation, not likely bearing 11 is mounted in the opening 6 of to easily become out of order, and otherwise the panel 5 and has rotatable therein a bush- 6:) well adapted to the purpose for which it ing 12 having a square bore for the recepis designed. tion of a square shank 13 which may slide With the above and numerous other objects therethrough, but is rotatable therewith.

15 in view as will appear as. the description A head 14. is formed on the bushing 12 above proceeds, the invention resides in certain the upper plate 15 of the bearing 11, and an 7' novel features of construction, and in the arm 16 is fixed or formed thereon to procombination and arrangement of parts as ject laterally therefrom terminating in a will be hereinafter more fully described downward extension 17 for engaging on top and claimed. of the contact C. This arm 16 will pref- In the drawing 1- V erably be constructed of spring metal. An 7+ Figure 1 is a top plan View of the rheostat operating knob 18 is fixed on the upper end embodying the features of my invention, of the shank 13, so that the said shank may Fig. 2 is a vertical section therethrough be readily rotated for swinging the contact taken substantially on the line 22 of arm 16 and engage its extension 17 with any Fig. 1, one of the contacts C. so Fig. 3 is a sectional view taken substanti- A pair of guide rods pierce openings in ally on the line 33 of Fig. 2, lookingupplates 15 and 15 of the spring 11, and wardly, registering openings in the panel 5 to deao Fig. 4 is a sectional view taken substantipend downwardly from the panels, These ally on the line 4-4 of Fig. 1, and guide rods 20 are held rigid to the panel by Fig. 5 is a diagrammatic showing of the means of nuts 21 as is clearly illustrated rheostat. in Fig. 4. The rods 20 are disposed in Referring to the drawing in detail, it will spaced parallelism, one to each side of the be seen that the numeral 5 denotes a panel center opening 6. A bracket 22 is fixed to of insulating material, in the present inthe lower ends of the guide rods 20 by nuts 90 stance. shaped s uare but, of course, may be 23. A bolt 24% pierces the panel 5 and is made of any ot er suitable formation. A engaged therewith by a nut 25, and also circular series of fixed contacts C is provided pierces. the bracket 22, and is held in engageon the panel 5, concentrically disposed ment therewith by nut 26.

about an opening 6. A ring 7 of insulating A sleeve of insulation 27 is disposed on {)5 material is fixed to the under surface of the bolt 24; and has a coil of wire 28 posithe panel 5 and is disposed concentrically tioned thereabout. A slide plate 29 has with the series of contacts C, and has prefopenings pierced by the guide rods 20. A erably a larger diameter than said series, so second slide plate 30 also has openings that the shanks of the contacts C which expierced by the rods 20, and the intermediate 100 tend through openings provided in the portion thereof is of an inverted U-shaped panels, may be positioned within the conformation as is indicated at 31. The lower fines of the ring 7, as is illustrated clearly end of the shank 13 is reduced and rounded i Figs. 2 and 3. as is indicated at 32 and plerces openings A wire is coiled about the ring 7 and has in the centers of the plates 29 and 30, and is ms its convolutions grouped, each group being securely engaged therewith by a nut 33. denoted by the numeral 8, and having a The bight portlon of the plate 30 1s prefresistance of predetermined value. for in erably welded or otherwise fixed to the intermediate portion of the plate 29, these connected portions being provided with a depending extension 3% having a spring brush mounted thereon for engagementwith the convolutions of the coil 28. The shank 30 is moved up and down through the panel 5.

The uppermost convolution or end of coil 28 is electrically engaged with a conductor 37 leading to a terminal 38 in the panel The contact C denoted specifically by the numeral 39 next adjacent the contact seat specifically denoted by the numeral 9, has a congestor 40 engaged therewith leading to the terminal ll on the panel. These terminals 38 and ll provide the terminals of the rheostat, in order that it may be placed in any desirable circuit.

ii hen the contact arm 16 is engaged with the contact C denoted specifically by the numeral 9, it will be seen that the circuit is opened in which the rheostat is disposed.

moving the contact arm in a clockwise direction, referring to Fig. 1, it will be seen that the current will flow from the terminal e1 through conductor 10, through one or more groups 8, through the arm 16, through the shank 13, through the brush through contact lf through bolt 2%, and through conductor 3'? to the terminal 38. This, of course, is presuming that the shank is in its lowermost position. However, if the shank is raised so as to engage one or the convolutions of the coil 38, it will be seen that the current must also pass through a portion of said coil, so that the resistance is increased. The coil 28 has a resistance of onehalf ohm.

This one-halt ohm is divided into fourteen equal parts by the fourteen convolutions of the coil 28, but of course the number of the divisions may be varied in accordance with the number of convolutions as may be desired. It is to be noted that the contact 43 is engaged with the bolt 24: while said bolt 24: is engaged with the conductor 37 through the ring It is thought that the construction. operation. and advantages of: this invention will now he clearly understood by those skilled in this art. The rheostat provides for a very fine adjustment in because of its coinpactness may be made smaller than other rheostats having the same adjustability. The structure is capable of being manufactured very cheaply and has been found useful in the radio art. as a control for generator seals in laboratories work, but, of course, is adaptable to general application in the electrical. field.

The present embodiment of the invention has been disclosed in detail merely by way of example, since in actual practice it attains the features of advantage enumerated as desirable in the statement of the invention and the above description. It will be apparent that numerous changes in the details of construction, and in the combination and arrangement of parts and in the sizes thereof may be resorted without departing from the spirit or scope of the invention as hereinafter claimed, or sacrificing any of its ad vantages.

Having thus described our invention, what we claim as new is 1. A rheostat of the class described including, in combination, an insulating panel, having an opening, a hub structure rotatable in the opening, said hub structure having a square bore, a square shank slidable through the bore, a contact arm fixed to the hub, an annular series of contacts on the panel concentric about the hub and engageable by the contact arms, a ring on the panel concentric about the opening therein, a coil forming a resistance unit disposed about the ring and having its convolutions arranged in groups, taps leading from the groups to the contacts, a bolt projecting from the panel, a coil forming a second resistance unit mounted on the bolt, and a brush on the shank engageable with the convolution's of the second coil.

2. A. rheostat of the class described including, in combination, a contact arm, means for mounting the contact arm to swing in a predetermined plane, a shank slidably engaged with the contact arm to rotate therewith and to slide perpendicularly to said predetermined plane, an annular resistance disposed so that the end of the contact arm engages therewith. a contact member j ournal ed on the shank to move rectilinearly therewith, an elongated resistance disposed perpendicularly to the predetermined plane, and guide means for maintaining the end of the contact member in engagement with the elongated resistance.

In testimony whereof we. affix. our signatures.

ORAN GROSE. HUBERT FISHER.

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